高超声速逆压梯度效应对壁面动载荷的影响

The boundary layer interference of hypersonic shock waves is the main cause of strong dynamic loads on the walls of hypersonic aircraft, and the presence of inverse pressure gradients further exacerbates the dynamic load environment on the walls. This article takes the flat plate and blunt rudder model as the research object, and adopts the wind tunnel pressure pulsation test method as the technical means. By designing different angles of blunt surfaces to simulate different intensity of reverse pressure gradients, the influence of hypersonic reverse pressure gradients on the time-frequency and spatial correlation characteristics of pulsation pressure is studied. The results indicate that the presence of inverse pressure gradients leads to earlier separation of turbulent boundary layers near blunt wings. As the rudder angle increases, the sound pressure level at the bottom of the blunt wing increases, and the pulsating pressure migrates from high frequency to low frequency. The spatial correlation identification results of wall pulsation pressure under the condition of no inverse pressure gradient have the most significant differences, and the spatial wave number identification results vary less due to pressure gradients. This article reveals the mechanism and law of the influence of the reverse pressure gradient effect on the hypersonic dynamic load environment, providing a certain support for the load reduction and vibration reduction design of the new generation hypersonic aircraft.